Clutch device for variable speed transmission mechanism



June 11, 1935. J. ECKHARD CLUTCH DEVICE FOR VARIABLE SPEED TRANSMISSION MECHANISM Filed Dec. 29, 1931 I5 Sheets-Sheet 1 HEN TOR. BY go w I ATTORNEY.

J.- ECKHARD 2,004,750

CLUTCH DEVICE FOR VARIABLE SPEED TRANSMISSION MECHANISM June 11, 1935.

Filed Dec. 29, 1951 3 Sheets-Sheet 2 INVENTOR.

ATTORNEY.

June 11, 1935. J EKHARD- 2,004,750

CLUTCH DEVICE FC JR VARIABLE SPEED TRANSMISSION MECHANISM Filed Dec. 29 1931 I5 Sheets-Sheet I5 1 lllillll 1, I," 45 ""000 INVENTOR.

ATTORNEY.

Patented June 11, 1935 UNITED STATES PATENT OFFICE I oL u'rcH DEvroE FOR VARIABLE SPEED TRANSMISSION. MECHANISM John Eckhard, Cincinnati, Ohio -Ap'plication December 29, 1931, Serial 1%. 583,721

invention relates to variable speed trans mission mechanism particularly for automotive vehiclesinawhich a change of speed iseffected bythesimple, straight-line movement of a tapered actuator within a tubular jack shaft thereby avoiding the cumbersome externalconstruction heretofore required for actuating the clutches of transmission mechanism operable on the samegeneral principle. a .wIt is my object to provide a transmissionlin which the 'clutchesfor actuating various speed changes are self-adjusting to compensate forwear on the clutching. surfaces of the clutches. Another object is the provision of clutches for, actuating the'different gears in which-the shoes carryingthe clutching-surfaces may readily be interchanged withoutthe use of different tools and-in fact inwhich the shoes may. be replaced without any tools being required. I :Theabove objectsin their broadest aspects as stated above, and other objects which will be noted in-the .cou'rs of the following description are illustrated in the :aocompa'nying' drawings, in which:" V .L a

Figure 1 is a longitudinal vertical section'on theplaneofthelinel-I of Fig. 4." L

:Figure- 21 is a partial vertical cross section on the plane of the line 22- of Figure 1.-' Figurel31 is a detail of'oneof the clutchshoe blocks andwthe cam fingertherein, together with a diagrammatic representation T of the actuator showing by solidlines the positions of the actu-' ator and finger when the actuator is moving in the direction of r the solid-arrow to' make the clutch operative, and showing by dotte'd lines the change'in position of the finger =asthe actuator passes in the direction of the dotted arrow without rendering the clutch operative.

Figure 4 is a vertical cross section on the plane of the line..44 of Figure-1. I

. In the preferredembodiment of my invention; as illustrated in these drawings, thedriving shaft I will be understood to'be the shaft that is connected tothe engine or motor of the ve-'- hicle,-and the casingfl has'the b ea ring3 at its front end for this shaft. At the rear end of the casing 2 is the hollow-boss 4 containing the roller'bearings 5 for theshaft'fi, which is understood tobe connected by suitableuniversal couplings' and a connectingshaft to thedifferential mechanism forfthe driving wheels of the ve hicle. 1 This shaft 6 -proj ects forwardly 1 of the front roller bearings "5, and ha's'keyed on it the spur gear 'I'. 'I'hed riving"shaft i has its rear end 'part 8 reduced in diameter, and the shaft 6 extends only part way through the hubof the gear 1, leaving spaoe-wherein'this reduced part 8 is'journaled by roller bearings 9.

" YThe direct driving clutch shell H] is bolted to the gear I by-bolts ll Inside this shell, the carrier 12 is keyed on the driving shaft l by the spline I3. The rear end of the hub ofathiscarrier l2 has an annular recess around thershaft 1 containing end thrust bearings 14. The car: rier! 2 has equally spaced around it radial channel guides l5, which have their inner ends at right angles to" their length, and have-guided in them respective'blocks 16, held thereinlby small yokes l1 secured across the channel guide .15 by cap screws I8. I The inner end of each block diver g'es 's omewhat from the end of the guide. The segmental shoes [9 have square hubs fittingin the outer end parts of the'respective guides 15, andhave suitable facings 2| to contact with the-inner surface of the shell 10 when pushed outward by the respective blocks l6. To make the clutches self-compensating for wear, each block lfiihas a recess containing a strong helical spring 22, and betweenthis and the shoe hub 20, shims 23 are placed. The purpose of the springs '22 is not 'onlyto'takeup or compensate for wear of the clutching surfaces, but also to maintainthe clutch'at adesired tightness of clutching; Each clutch shoe I9 is connected by two springs-24,'one' at each side of theguide I5, to' screws 25 in the wall of the clutch carrier I2, which'springs thus hold the clutch shoe inward against the shims 23. To prevent the clutch shoe I9 from slipping through theopen. end of the shell H], a tongue 26 is held on'each small yoke lby'a screwl'l and extends out and bears resiliently againstaboss of the shoe. The tongue'26 may be swung aside on itsscrew 21'- for removal and replacement of the shoe without the use of tools. Forwardlyfrom this clutch mechanism just described, a hub 28 slides on the spline l3 and turns in a ring 29, having ball bearings. The ring has. lateral trunnions 30 embraced by the, respective .members of a fork 3| fixed on the transverse shaft 32 below the hub 28. Wedges 33 are pinned'on this hub 28, and project therefrom between the hub of the 'carrier l2 and the inner ends of the respective blocks [6. Thisshaft 32 extends out through one side of the casing 2, and has fixed on it the lever arm 32 I The parallel or jack shaft 34 is journaled in a the front bearing 35, and the rear bearing 36, in-thecasing 2 and is tubular. It has keyed on terior of the shaft 34 and is shaped with a taper it and meshing with the gear 1 of the driven shaft 6, the spur gear 31. Also it has loose and free to turn relatively to it, the three gears 38 39 and 40. The drive shaft I has keyed on it the three gears 4|, 42 and 43, the latter two port and guide the clutch shoes l9a and blocks 41 held by yokes 48 and screws"; the block 41 containing the spring 22, withlwashersorh shims 5| between it and the shoe l9a. The

clutch is in these respects the same as' the'df {positionhowever, theiactuator 58 engages the fingers 52- of the clutch of the rearmost one of rect driving clutch above"describe'd.. The" block 41, however, has a finger 52 pivoted in a crotch in its lower end on a pin 53 and extending. in--'* side the tubular shaft 34; through a slotv 54 in theshaft. Also therev is-a yoke 55- embracing the shaft 34 and bolted to diametrically opposite parts of the rim of the -shell 45, thus giving the shell a more extended support on the. shaft 34. 4 I I,

The other two gears 39 and 48Qhave clutch mechanisms the same as just described for the gear 38, but have these mechanisms bolted onto their rear faces. The parts of these clutch mechanisms therefore are numbered the same as those of the clutch mechanism of the gear 38, and the cam fingers 52 of these mechanisms extend into the interior of the shaft 34 through slots'56 and 51, respectively; The actuator 58 has a middle part that fits slidingly in'the intoward bothends from this middlepart, and has around this middle part a circumferential shallowgroove 53. The actuator has an opening through itfrom end to end'gin which fits'the reduced end part of the operating rod 60,; which extends out past the rear end .of the tubular shaft 34 for connection to suitable manipulate ing mechanismon thevehicle.- t p Eachfinger 52 engages the end of the-slot in the shaft 34, limiting its swin'ging inone direction so that the finger'is 'held'in relation to the block 41 as a thrustelementaby means of which the actuator 58 wedges the, block' radially out ward until the actuator groove 59 receives the end of the finger. The finger is free to, swingin the shaft slot-in the other direction, allowing passage of the actuator 58, without. wed'ging the finger and block 41 outward. This makes it unnecessary to clutch for-an intermediate speed when changing from a speed higher to. a speed I lower than the intermediate speed.., vA nose 6| on the finger 52 engages'thecrotch' of the block 41 to hold the finger in 'itsjextended position for entrance to the, shaft *slot when assembling the mechanism on the shaft 34. i i V In the front end of the tubular shaft 34 a bushing 62 is slidablymounted. A lever 63 has atransverse fulcrum 64 on the frontend of the casing 2 and extends upward into contact with the bushing 62 and extends down'wardand has pivoted to it one end of a rod 65, .whichextends backward and has its front end pivoted to the upper end of the lever 32a, which operates the direct driving clutch. A helical spring 66 is compressed between the front connecting head ofthis rod 65 and a lug 61 on the side of the casing 2 and holds the rod yieldingly forward, with the wedges 33 withdrawn from under the blocks I6. In operating the device, if the actuator 58 is moved to its extreme forward position, it presses the bushing 62 outward, which acts through the operative connections just described to move the wedges 33 under the blocks l6, pressing these blocks radially outward and clamping the shoes l9 against the inside; of the shell I; thus connecting the shafts I and 6 together for direct transmission, which affords he highest s e'i a When the actuator 58 is drawn backward, its rear end part pushes the fingers 52. of the for- "wardmost part of gears 40 and 43 backward without operating the clutch; and upon reaching "the fingers 52- of the clutch for the gear the same action occurs without operating the clutch of'this gear 39. Upon reaching the rearmost the three gears by wedging radially outward on these fingers, which restand slide againstfthe rear ends. ofthe slots 54 in the tubular shaft 34. This wedges the blocks 41 radially outward,

Moving the actuator 58 forward, it willen-H counter the fingers52 of the clutchofthe middle pair of gears 38 and42 and will wedgeoutward on these fingers, causing this ,clutchto connect the gear 33 to the tubular shaft 34, which gear, is being-drivenbythegear 42 fixed onthe'driving shaft]; This will drive the. tubularshaft 34 in direction reverse to that .ot'the .driving shaft I, and will drive the shaft 6 by means'of the gears31 and 1 in the same directionas the driving shaftt vi Upon movingthe actuator 58 farther forward;

itwillact in the same way, on the fingers. of-

the clutch, of the {gears 48 and :43, sozthat the drive of the shaft will be from the driving shaft I through the gears 43 and-fichetubular shaft 34 and the gears 31 and 1 in the same direction asthat derived from the1middle' set of gears, butat adifierent speed. The groove 59 around the actuator 58 allows the block. 41 :to. slip. radially inward slightly but still holding the clutch shoeslSa in driving contact with the shell .45.

By this engagement in this groove 58; the finger" 52 is prevented from swinging awayfrom its sus-. taining position under theinfiuence of vibration of the mechanism. As clearly shown. inFigure 3, a'small spring. contained in a recess :69 in the block 41 presses a small plunger 18 against a part of the top-of the finger 52, which is horizontally disposed from, the pivot pin 53 sufficient; ly to permitthis: small spring normally to hold the finger 52 against, the end of theshaft slot 54, 56, or 51, asthe case may be,.refadv for the clutch-operating, wedging action of the actuator clamping the shoes |8a of this clutchagainsti the i The result will be that 58, as above described. However; this spring allows the fingerv 52 to yield upwardly asindicated by the dotted linesiri Figure 3, so that the actuator 58 may pass thereunder in one direction without operating the clutch as before described.

It will be seen from the foregoing descriptionthat with the rearmost position of the actuator 58 the vehicl 'willbe dr'iven backward; andthat "as the actuator- SBQ iS' pushed forward, succes- 's'ively higher"speeds will seemed. As-the gearsae arid' 4'fl are successively clutched to the tubular" 'shaft -34, thenthe driving I shaft "and shaft 6 aredirectly connected by the "operation through thebush'ing 62 at the forwardmost position of the actuator 58.

Direct connection of the drivingshaft I and shaft 6 is used to avoid imposing the load on two such rapidly rotating gears as the gears I and 3'! would have to be in order to attain this high speed alone through the tubular shaft in the way that the lower speeds are attained. Of course in this direct drive the gear 1 rotates the gear 31, which rotates the tubular shaft 34, but as there is no load on these parts this is not objectionable. The result to be avoided is the loud noise which is made by such rapidly running, heavily loaded gears.

The gears 31 and 38 are spaced apart by a thin sleeve H around the shaft 34, and a collar 12 around this shaft spaces the inversely disposed clutch mechanisms of the gears 38 and 39 apart, while another collar 13 spaces the gear 39 from the clutch mechanism of the gear 40. The gear 40 and gear 31 bear axially against the bearings 35 and 36, respectively, of the casing 2. Thus the loosely mounted gears and their clutch mechanisms are prevented from having end play, and are maintained in mesh with the respective gears 4|, 42 and 43.

The mechanism thus will be seen to be comparatively simple and compact, and has the especial advantage of being operated by various simple and easily understood manipulations of the single actuator 58, without the necessity of a special clutching mechanism since the throwing into operation of any particular pair oftransmission elements is effected by a clutching operation.

During positions between engagement of the member 58 and the fingers 52, there is always a condition of neutrality.

I have set forth a preferred exampleof my in vention rather specifically, but it will be understood that the invention is capable of considerable modification to meet conditions in practice without departing from the scope and spirit thereof,

and that therefore I am not limited to such 1 precise disclosure, but what I claim as new and desire to secure by Letters Patent, is:--

l. A clutch for clutching together a shaft and an element rotatable on the shaft, comprising a shell connected to the element, a carrier connected to the shaft and having radial guides, shoes guided by the guides to and from the in terior of the shell, means movable on the shaft, means to transmit movement of said means to the shoes for pressing the shoes to the shell, and means holding the shoes to the guides, movable by the hands without the use of tools, to

permit removal of the shoes from the guides.

2. A clutch for clutching together a shaft and an element rotatable on the shaft, comprising a shell connected to the element, a carrier connected to the shaft and having radial guides, shoes guided by the guides to and from the interior of the shell, blocks guided by the guides to move the shoes, means movable on the shaft to impart movement to the blocks, yokes removably secured to the carrier to hold the blocks to the guides, and means holding the shoes to the guides, movably mounted on the yokes and movable by the hands without the use of tools,

to permit removal or the shoes from the guides.

toward the shell, means movable on the shaft to impart movement to the blocks, yokes secured across the guides and holding the blocks in the guides, and resilient tongues pivoted on said yokes, holding the shoes in the guides and adapted to be swung on their pivots away from the shoes to permit removal of the shoes.

4. A clutch for clutching together a shaft and an element rotatable on the shaft, comprising a shell connected to the element, a carrier connected to the shaft and having radial guide channels, shoes presented toward the interior of the shell and having extensions sliding in said guides, blocks slidable in said guides, springs compressed between the blocks and the shoe extensions, springs stretched from the shoes to the carrier in opposition to and Weaker than the compressed springs, yokes secured across the guides and holding the blocks in the guides,

resilient tongues pivoted on the yokes, holding the shoes in the guides and adapted to be swung on their pivots away from the shoes to permit removal of the shoes, and means movable on the shoes to the shell.

5. A clutch for clutching together a hollow shaft having slots in its wall and an element rotatable on the shaft, comprising a shell connected to the element, a carrier connected to the shaft and having radial guides, shoes guided by the guides to contact with the interior of the 6. A clutch comprising a clutch member operated for clutching together a shaft having a device movable therein, and an element ro- Y shaft to move the blocks and thereby move the tatable on the shaft, by means of mechanism actuated by said device, in which the mechanism comprises resilient means by which it transmits the clutching pressure from said device to the clutch surfaces, and a shim to adjust'said resilient means, and in which the device actuates the mechanism by members comprised in the device and the mechanism, respectively, by engagement when the device is moved to the element in one direction, and in which said members are relatively yielding, without actuation of the mechanism, when the device is moved Vice is prised in the device ,and -the mechanism, respectively, by engagement when ,the demoved to the element in one ammo surfaces, pr ven in flur flve: M ,maintein' the plumbing relation tlmmutugl gegement' of said surfaces being the resilient means, which permitsthepurhnw to separate when the device ismovedJawey'imm I the element. v JOHN ECKHARDM 

